Hello fellow Alembic-heads! This is my first post on the forum but rather sadly is not a particularly happy one...

After 20 odd years of playing bass I finally found my ideal Alembic after years of waiting and saving. It arrived safely in one piece earlier today. It's a wonderful Series 2, 3/4 size point shape body with burl maple front and back. It's actually one of the featured customs from 2000 on the Alembic website ('Fire and Ice').

However...on plugging everything in (using the DS5 bass output to run a mono signal into my practice amp and with mono selected) it became evident that something's not quite right...

Basically, it doesn't matter how much I tweak the filters or CVQs all I get is the same P-bass kind of neck pick up sound. No bite or glassy S2 tones at all. Rotating the pots results in virtually no variation of tone - it's just a warm, bassy P-bass imitation.

Also if I turn the pickup selector from off position to the first position (bridge pickup?) I get no sound at all. Positions 2 and 3 sound almost the same, so I'm guessing this is just isolating the neck pickup.

Now, before I get flamed for not trying before you buy with such an expensive purchase (:-)) the bass was purchased from a store in southern Germany and it simply wasn't feasible for me to travel there to try it out. The shop was very helpful and are a prolific Alembic dealership so I trusted that they were selling the bass as described, e.g. like brand new.

Does anyone here have any thoughts as to what might be wrong? It might be that I need a new pickup selector but would this alone be causing the lack of tonal variation from the filters/CVQs?

I've taken the back covers off and everything seems connected and in good order.

Sorry my first post isn't a happy 'hello everyone' but, as you can imagine, I'm feeling rather frustrated, confused and annoyed.

There should be 4 positions on the pickup selector switch. The most counter-clockwise rotation is stand-by, and will have no sound at all. Depending on how the pickups are plugged in, the next position is one pickups, the third is both pickups and the fourth is the other pickup. While you are in positions 2,3, and 4 tap the pickups lightly with a screwdriver or other ferrous object to confirm which pickup is responding in which position. Also, do make sure the DS-5 is in the mono position or you will only be getting one pickup from the bass output.

What you are observing sounds like you are getting the signal from only one pickup. We have to figure out if you have a problem with the pickup itself, the electronics, the cable, or the power supply. So some testing is in order.

Have you tried the bass with batteries and the 1/4" output? That is an excellent test and will let us know if you have an issue on the bass or off the bass. Please report back with these results and we'll go through step by step what needs to be done.

One other thing you can try is set the DS5 in stereo mode. Have the pickup selector set for both pickups. Try the Bass output with your amp. This would normally be the neck pickup. After that try the Treble output to your amp. This will normally be your bridge pickup.

Welcome here and congrats with an awesome looking (and hopefully soon sounding) bass! Sorry to hear about the false start with the instrument you've been waiting for so long... :-(

But you found the club and Lothar is a great guy, so you be in sonic heaven in no time :-)

Can you post pictures of the electronics? Make sure nothing is touching the shielded paint inside the cavities, also make sure all connectors are firmly in place. The pickups connect to the board behind the square cover (with 4 holes in it) You can switch the neck/pickup connectors to rule out/confirm a failed pickup. The function of the 4 trimpots behind the holes is explained here: http://alembic.com/club/messages/16271/50896.html (check the gain pot for the bridge pickup)

fc_spoiler: I'll try and post up some pics of the electronics later tonight. Everything looked in order but another check wouldn't go amiss. I did look under the trim pot cover and again all seemed OK. The trim pots all seem to be set at dead centre.

Yes, I was hoping for that wah effect when turning the filters but I get nothing...

Mica - I'll also try the test that you suggested and report back. My selector swith definitely only seems to have 3 clickable positions. The knob is slack though and needs tightening up, if I can find a small enough hex key... Yes, my DS-5 has a voltage switch on the back and it's set to the correct place, i.e. 230v for the UK showing on the red plastic indicator.

First I took the back covers off again to take photos (which I will attempt to upload later) and to check connections, loose wiring, etc. Everything looks solid, no obvious dry solder joints, no exposed wires touching the shielding paint. Under the trim pot cover I checked the 3 brown pick up plugs. Again, all seated firmly but I wiggled them home to make certain. I did the same with the black multipin plug with the rainbow ribbon wire. Again, all seated nicely.

So, onto testing the pick ups...

With battery power only, using a standard 1/4" lead and using Mica's screwdriver test with both filters and CVQs wide open, here's what I get with each selector position;

Position 1: bridge pick up only Position 2: both pick ups Position 3: Neck pick up

(interestingly, listening through headphones plugged into my amp I also now heard more tonal variations when using the filters and CVQs)

same test using the DS-5 set to mono with a standard 1/4" lead from the bass output into my amp, filters and CVQs wide open;

Position 1: no sound Position 2: neck pick up Position 3: neck pick up

And just for comparison, still in mono but with the lead from the DS-5's treble output into the amp;

Position 1: bridge pick up Position 2: bridge pick up Position 3: no sound

So in summary, using battery power I seem to be getting sound from all 3 pick up selector positions. However using the DS-5 I'm getting one or the other but not both at the same time.

I haven't yet been able to play through the amp at loud volume (sleeping kids and all that...) to test the sonic variations but it would seem that battery power might give me a better sound palette but the DS-5 isn't happy. somehow...

A couple of final points to note;

1) The mono/stereo switch on the front of the DS-5 got broken off in transit from Germany but I checked that it's set to mono by using a small precision screwdriver to make sure it was flicked all the way down.

2) I looked inside the DS-5 and nothing seems loose or out of place. Again, very solidly put together and soldered.

As I mentioned earlier, my pick up selector has 3 clickable detents, i.e. from it's furthest position counter-clockwise I can click it into 3 positions clockwise, so the 'zero'/'rest' position is off. Interestingly the black knob seems to be upside down, meaning that it's pointing down towards the filter knobs rather than upwards, but I guess it's just been refitted this way - the switch still rotates the same way.

So there you have it. Not sure exactly what the problem might be but using the DS-5 is causing some issues, whereas battery power is giving both pick ups.

Or maybe I'm just being completely stupid somewhere along the line...! :-)

I would say it is the stereo/mono switch in the DS5 that is causing the problem since you say it was broken in transit and it is working through the 1/4" jack on the bass. When the toggle was broken it also damaged some of the contacts inside the switch. The switch is a C&K 7201.

Welcome to the Forum David and congratulations on acquiring that fine bass! Sorry you're having some initial trouble but you've come to the right place for answers!

I'd agree with Keith - the stereo/mono switch on the DS-5 sounds like the culprit. Even if it appears to be in the correct position it doesn't seem to be operating as designed. It could also be that the switch was never moved from it's stereo position and needs to be exercised, but that's hard to do if the actuator is broken off...

So the temporary fix; #1. use the batteries and mono 1/4" output. #2. does your amp channel have two inputs? Try two 1/4" cables from the DS-5 to those inputs. That may do the summing for you. #3. separate amps for the separate pickup outputs. But be careful, you will fall in love with this giant tone and it will make life difficult. Ha!

Mica can probably ship you the exact right switch if you wish, or you could find an equivalent and have it installed (Mouser would be a good source in the UK).

The only remaining question is about your pickup selector switch. Are you certain there is no 4th "off" or "standby" position? That would be extremely odd and would appear as a custom modification in the instrument's file at HQ. The master volume control can serve the purpose of muting the instrument in the meantime, and, I suppose you can just get used to using that just like on a passive bass...

"As I mentioned earlier, my pick up selector has 3 clickable detents, i.e. from it's furthest position counter-clockwise I can click it into 3 positions clockwise, so the 'zero'/'rest' position is off."

So I guess this is the regular 4 way switch :-)

Huge +1 for the DS-5 switch... I'm not sure if it can be harmful for the electronics, but I would suggest to not use it again until it's fixed.

Btw: If you have troubles getting the pics to the 150kb size limit, you can send the original pics to the email address in my profile ;-)

"Sometimes guys who play lets say "enthusiastically" will turn the pointer knobs around so they don't bang into them. You can choose which way you want them to point via the two tiny set screws."

You can also get a knurled knob to use instead of the pointer knob. This is what I did on my Series and have thought about doing to my Brown Bass. You can see what the knurled knob looks like if you scroll to the last picture in this thread

While the switches have a long life they are not that robust when damaged like you described.

I'm sure Alembic would be able to send you a complete switch assembly. You would need to contact Mica to determine the cost, etc. It usually works better if you can call them first to talk about it. They are usually available after 10AM PDT and before 4PM PDT. Otherwise try e-mailing them at the sales or help addresses located here and update this thread that you have e-mailed them.

One other thing came to mind. Be careful if you try to remove the volume/filter knobs. From the pictures I saw in the archive they look to be collet knobs. These have a removable cap then you loosen the collet from the shaft. It has happened more than once that someone thought they were friction style knobs and ruined a pot. Of course they might have been changed, if so post a picture if you are unsure what type you have.

Correct hex wrench size now ordered and I'm pleased to report that, following my first gig with it last Saturday, everything is working fine using battery power.

I've looked into getting a replacement DS-5 switch from Mouser here in the UK but there seems to be several types of C&K 7201 availabe (they all look similar and are 27v but have different letter suffixes after the 7201 bit). Is there a sepcific one I should use?

Thanks again Keith and Mica - fantastic support! I've now ordered a couple of switches from Mouser so will report back when I've dusted off my soldering iron and (hopefully) got the new switch safely installed and tested...

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